Physicians and other healthcare professionals (collectively, “physician”) commonly use catheters in a variety of medical procedures. Catheters guide and introduce a variety of medical devices, guide wires, drug delivery tools, therapeutic agents (e.g., drugs, medication, narcotics, antibiotics, pharmaceutical products, and/or medicinal agents, therapies, or substances) and other operative instruments or devices (individually and collectively, “instruments”) into the body percutaneously or through a working channel of an endoscope or accessory channel to be used with an endoscope. Thus, catheters often serve as a highway—a temporarily established path—for placing, introducing, exchanging, and replacing instruments during a medical procedure, thereby eliminating the need for performing delicate navigation procedures for each instrument passed into a vessel passageway.
A vessel passageway includes any lumen, chamber, channel, opening, bore, orifice, flow passage, duct, organ, or cavity for the conveyance, regulation, flow, or movement of bodily fluids and/or gases of an animal. For example, physicians frequently use catheters in medical procedures that involve the passageways of a heart, blood vessel, artery, vein, capillary, bronchiole, brachial, trachea, esophagus, aorta, intestine, bile duct, pancreas, liver, gall bladder, ureter, urethra, fallopian tube, and other locations in a body (collectively, “vessel”) to name a few. Similarly, physicians may place catheters through a working channel of an endoscope, or a channel endoscope accessory device, during endoscopic medical procedures that involve these vessel passageways.
In order to negotiate a typically tortuous path of a vessel passageway or to avoid obstacles during insertion of a catheter through vessel passageways, conventional catheters include hollow flexible tubes with a tactile first end and a flexible second end. The first end forms the end that physicians sometimes grip or otherwise secure, and the second end forms the end that physicians position at or near the target site. The hollow tube normally comprises a substantially circular cross section to mimic the configuration of a typical vessel passageway or the channel of an endoscope or endoscope accessory device.
Maneuvering the catheter second end through the vessel passageway and to the target site often presents a time-consuming endeavor for the physician. In order to obtain a desired maneuverability of the second end, conventional catheters commonly employ one of several approaches and features.
In one type of catheter, the second end moves substantially passively. As the physician inserts the catheter through the vessel passageway, the catheter follows the path of the vessel passageway. Should this catheter enter the wrong vessel opening, such as in a case of a bifurcated vessel pathway, the physician must engage in a series of steps of manually withdrawing the second end from the wrong vessel opening, and then reinserting the second end until it enters the desired opening. In order to accomplish this feat, the physician may also rotate the catheter about the catheter longitudinal axis. A physician may need to make numerous attempts with the passive catheter to gain access through the desired opening. Any of these steps increases the length of time for the medical procedure and possibly patient discomfort.
The present inventions solve these and other problems with a steerable distal second end portion and/or sterrable distal tip.
In another type of catheter, the catheter second end may include a slight pre-formed bend. Thus, the catheter second end follows closer to the wall of the vessel passageway than it does the center of the vessel passageway. Upon encountering a choice of taking two or more vessel openings (again using a bifurcated vessel pathway as an example), the physician rotates the catheter about the catheter longitudinal axis until the catheter second end points toward the desired opening. These catheters require a certain amount of torque-ability, however, which refers to the extent to which a catheter transfers a torque in a one-to-one relationship from the first end to the second end without a whipping effect resulting from torque build-up in the catheter. Also, as the catheter is inserted deeper and deeper into a patient, and as the catheter navigates through a tortuous pathway of vessel openings, catheter rotation may become more difficult and may present the patient with some discomfort.
The present inventions solve these and other problems with a steerable distal second end portion and/or steerable distal tip that are substantially straight in a relaxed portion and articulates from a relaxed position to a bending position.
In yet another type of catheter, cables within the catheter help to maneuver the catheter second end. These cables typically comprise a wire having a first end attached to the catheter first end, and a second end attached to the catheter second end. The physician actuates one or more cables by pulling proximally, pushing distally, or rotating the one or more cable first ends, which translates a corresponding movement in the cable second ends and, as a result, the catheter second end. As is conventional, “distal” means away from the operator when the device is inserted into a patient, while “proximal” means closest to or toward the operator when the device is inserted into a patient. Maneuvering a catheter with cables requires a catheter having two competing criterion. The catheter must be sufficiently flexible to avoid damaging the vessel through which the physician advances the catheter. Conversely, the cable must have suitable column strength sufficient to allow the cable to be pushed, pulled, and rotated through the endoscope channel or a patient's vessel passageway. Moreover, a cable typically extends through a substantial length of the catheter, which cable length tends to increase the variable that the catheter may kink, buckle, bow, or prolapse as a result of the tortuous path the procedure may require.
The present inventions solve these and other problems with a steerable distal second end portion and/or steerable distal tip that have an elastically fluid-distensible occluded distal end offset from a substantially central longitudinal axis.
Other catheters might consider employing fluid force to steer the catheter with a fluid actuating lumen that extends the length of the catheter. One problem they would have with fluid forced steerable catheters is the tendency to balloon the fluid actuating lumen as fluid is forced through the actuating lumen to the distal end. Forcing fluid through the actuating lumen causes the lumen to expand radially (balloon) along the length of the actuating lumen, thereby reducing the fluid force in the longitudinal direction such that there is inadequate fluid force at the distal end to cause the catheter to bend.
The present inventions solve these and other problems by having a larger outer diameter (hence, greater thickness to transmit fluid force) that steps down to a smaller outer diameter at the steerable distal second end portion and/or steerable distal tip.
Other problems one would have if considering a fluid forced catheter is radial ballooning of the actuating lumen at the sealed distal end that is intended to cause the catheter to bend. The present invention solves these and other problems with an expansion resistant outer reinforcement.
Also, one considering fluid force for a steerable catheter would, given the problem with collapsing inward, limit the functionality of the steerable catheter to steering and possibly a small lumen for contrast fluid. As a result, their catheters would only be usable for placing, introducing, exchanging, or replacing instruments having a central lumen that may pass over the catheter in a back-loaded or front-loaded medical procedure. Consequently, the catheters would not be replaceable with a wire guide.
The present invention solves these and other problems with a fluid forced catheter adapted with a tool receiving passageway disposed with the catheter and extending to a steerable distal second end portion. Additionally, the passageway may have a compression resistant inner reinforcement.
It is therefore desirable to provide an alternative to the above-described conventional catheters that eliminates or reduces one or more of the limitations or disadvantages discussed above.